Recently (not so) theres been a new feature that things that teleport can be traced with a hand tele via bluespace rift this is cool and all but doesnt apply to many antags such as abducters / clockies or other syndi stuff that would benefit from it
However
when heretics send somebody to the shadowrealm by sacrificing them it can easily be traced ( so can their blade but thats liked intended i think ) that aside half the shadowrealms are unsuitable for NT colonization making it Impossible to return and only 1 of them can be dismantled and conquered
TLDR:
NT cannot do a reverse Oblivon crisis and rescueing people is uneffective as they get TP’ed anyway
+
Being Stuck by accident in Hermaeus Mora land is boring